It is well known to use scrubbers or other wet chemical absorption processes to strip the hot flue gases of their contaminants, such as sulfur oxide and the like. Such chemical absorption systems are typically calcium, magnesium or sodium based processes. Generally, in accordance with such processes, the hot gas is washed in an up flow gas-liquid contact device with an aqueous alkaline solution or slurry. This permits the removal of the desired contaminants in a controlled manner and to a controlled degree (efficiencies of upwards of 90% or more are possible).
One typical example of such scrubbers is disclosed in U.S. Pat. No. 4,263,021. While this patent may be considered a standard in the industry, improvements to this technology comprise the subject matter of this invention. Other examples of related technology are cited in this patent, namely: U.S. Pat. No. 3,489,506 to Galstaun et al., U.S. Pat. 3,615,199 to Terrana, and U.S. Pat. No. 3,834,129 to Darlinger et al.
This typical scrubber is currently referred to as a tray or spray/tray scrubber because some means of distributing the gas and liquid within the tower, such as a tray or the like, is incorporated. This tray evens the flow of the flue gas within the tower for more uniform distribution therethrough and also acts as a mass transfer device.
It is an object of this invention to advance existing wet flue gas desulfurization technology by improving spray tower gas distribution. Another object of this invention is to increase both reagent utilization and the rate of mass transfer of sulfur oxides and/or other contaminants from the gas phase to the liquid phase with or without the use of additives. Still another object of this invention is to enhance the uniform mixing of the gas and the liquid by improving gas flow profiles at the face of downstream liquid entrainment devices. Yet another object of this invention is to improve absorption by varying flow velocity, liquid flux rates, pH, suspended solids in the chemically reactive liquid slurry, and the open area of the trays. These and other objects of this invention will become obvious upon further investigation.